reg_dumper: change and fix behavior when using dump files

Before this patch, handling dump files was wrong:
- when HAS_PCH_SPLIT was specified, intel_reg_dumper segfaulted inside
  intel_check_pch()
- the "devid" variable was used but not set
- there was no way to specify the device id of the machine used to
  generate the dump file

This patch fixes this behavior with the following changes:
- the HAS_PCH_SPLIT variable is gone
- there is now a '-d' argument that can be used to specify the device id
  used to interpret the results
- when a dump file is used but the '-d' argument is not provided, an
  Ironlake machine is assumed

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

man/intel_reg_dumper.man

@@ -4,7 +4,7 @@
 .SH NAME
 intel_reg_dumper \- Decode a bunch of Intel GPU registers for debugging
 .SH SYNOPSIS
-.B intel_reg_dumper [ file ]
+.B intel_reg_dumper [ options ] [ file ]
 .SH DESCRIPTION
 .B intel_reg_dumper
 is a tool to read and decode the values of many Intel GPU registers.  It is
@@ -14,11 +14,20 @@ argument is present, the registers will be decoded from the given file
 instead of the current registers.  Use the
 .B intel_reg_snapshot
 tool to generate such files.
-.SH ENVIRONMENT
+
-.BR HAS_PCH_SPLIT
+When the
-.PP
+.B file
-If set, decode as though the GPU has a PCH split.  This is only necessary for
+argument is present and the
-Intel HD (Ironlake) and later register dumps in files; live decodes get this
+.B -d
-correct automatically.
+argument is not present,
+.B intel_reg_dumper
+will assume the file was generated on an Ironlake machine.
+.SH OPTIONS
+.TP
+.B -d id
+when a dump file is used, use 'id' as device id (in hex)
+.TP
+.B -h
+prints a help message
 .SH SEE ALSO
 .BR intel_reg_snapshot(1)

tools/intel_reg_dumper.c

@@ -30,9 +30,10 @@
 #include <stdio.h>
 #include <string.h>
 #include <err.h>
+#include <unistd.h>
 #include "intel_gpu_tools.h"
 
-static uint32_t devid;
+static uint32_t devid = 0;
 
 #define DEBUGSTRING(func) static void func(char *result, int len, int reg, uint32_t val)
 
@@ -2072,21 +2073,61 @@ intel_dump_regs(void)
 	}
 }
 
+static void print_usage(void)
+{
+	printf("Usage: intel_reg_dumper [options] [file]\n"
+	       "Options:\n"
+	       "  -d id   when a dump file is used, use 'id' as device id (in "
+	       "hex)\n"
+	       "  -h      prints this help\n");
+}
+
 int main(int argc, char** argv)
 {
 	struct pci_device *pci_dev;
+	int opt;
+	char *file = NULL;
 
-	if (argc == 2)
+	while ((opt = getopt(argc, argv, "d:h")) != -1) {
-		intel_map_file(argv[1]);
+		switch (opt) {
-	else {
+		case 'd':
+			devid = strtol(optarg, NULL, 16);
+			break;
+		case 'h':
+			print_usage();
+			return 0;
+		default:
+			print_usage();
+			return 1;
+		}
+	}
+	if (optind < argc)
+		file = argv[optind];
+
+	if (file) {
+		intel_map_file(file);
+		if (devid) {
+			if (IS_GEN5(devid))
+				pch = PCH_IBX;
+			else
+				pch = PCH_CPT;
+		} else {
+			printf("Dumping from file without -d argument. "
+			       "Assuming Ironlake machine.\n");
+			devid = 0x0042;
+			pch = PCH_IBX;
+		}
+	} else {
 		pci_dev = intel_get_pci_device();
-		devid = pci_dev->device_id; /* XXX not true when mapping! */
+		devid = pci_dev->device_id;
 
 		intel_get_mmio(pci_dev);
+
+		if (HAS_PCH_SPLIT(devid))
+			intel_check_pch();
 	}
 
-	if (HAS_PCH_SPLIT(devid) || getenv("HAS_PCH_SPLIT")) {
+	if (HAS_PCH_SPLIT(devid)) {
-		intel_check_pch();
 		ironlake_dump_regs();
 	}
 	else if (IS_945GM(devid)) {